JP2898756B2 - Oil tolerance reinforced strip - Google Patents

Description

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to improvements in disposable items such as diapers, incontinence products, disposable clothing, feminine hygiene products, and the like.

Baby disposable diapers are often used with powders and oils that parents put on their babies. Such powders and oils often contaminate the outer backsheet of the diaper. Typically, powder or oil is transferred from the parent's hand or from the baby's body to the backsheet of the diaper. One of the complications of such powder and oil contamination is that the traditional adhesive tab closures used on diapers adhere to the backsheet outside the diaper, leaving talc and especially oil-contaminated surfaces poorly covered. Is a point that does not adhere.

U.S. Pat.No. 4,163,077 discloses that the adhesive for the fastening tab is a solid and liquid polyterpene type tackifier formulation and a specific formulation of a synthetic block copolymer.
Such diaper closure systems have been proposed. This adhesive has limited adhesion to diapers contaminated with talc or powder, such as polyethylene backsheets typically used in commercial diaper constructions. However, this adhesive composition does not address the problem of adhesion to oil-contaminated diaper substrates.

The problem with conventional pressure sensitive adhesives of adhering to oil contaminated surfaces is addressed in US Pat. No. 3,991,002. The above specification describes a method for improving the adhesion of a conventional pressure-sensitive adhesive tape to a substrate contaminated with oil by treating the substrate contaminated with oil with a primer. The primer comprises a rubber phase of an ABA triblock copolymer such as a styrene-butadiene-based or styrene-isoprene-based block copolymer, a resin compatible with the conjugated diene portion of the block copolymer, and a monovinyl resin of the block copolymer. A resin phase that includes a resin that is compatible with the aromatic hydrocarbon moiety (ie, styrene). These components are present in solution and then applied as an aerosol to stabilize the oil contaminated surface for subsequent adhesion. The patent states that the conventional method of bonding to oil-contaminated surfaces is a cumbersome and time-consuming cleaning method. However, the primer solutions proposed in the above patent specifications are still impractical for most consuming applications, especially diapers applied to babies.

An object of the present invention is to solve the above problems.
In particular, it is an object of the present invention to provide a diaper structure provided with a reinforced tape adhesive zone having oil contamination tolerance.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a disposable garment, generally a diaper, in which an adhesive fastening tab is permanently attached at a first end to one of the corners of the garment. A free second end of the adhesive fastening tab is provided to adhere to the reinforced outer surface of the garment, and the two corners of the fastening tab connect the corner to the reinforced surface to close the garment. Strengthened by a reinforced film or web layer bonded to the thin outer film or web layer of the garment. The reinforcement layer comprises a porous film or web whose pores preferably contain at least a small amount of an incompatible oily or liquid polymer. The porous reinforcement layer provides oil contamination tolerance and strengthens the thin outer film against tearing when peeling the free end of the adhesive fastening tab.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a conventional diaper structure using a microporous reinforced layer of the present invention, shown in a worn configuration.

DETAILED DESCRIPTION OF THE INVENTION The oil contamination tolerant adhesive closure system of the present invention will be described with reference to conventional baby diapers, but such closure systems will be used for adult incontinence garments,
It can also be used in other applications that use adhesive fastening tabs, such as disposable medical gowns, hats, packaging systems, feminine hygiene products, and the like.

FIG. 1 shows a conventional diaper structure. Diapers 10
A thin liquid-impermeable outer backsheet 2 and a liquid-permeable inner coversheet 3 are provided. Between the back sheet 2 and the inner cover sheet 3 is a core of absorbent (not shown). Adhesive fastening tabs 4 are provided at two laterally opposed side edge regions 7 at the first end of the diaper. The second end on the diaper back sheet 2 has a porous reinforcing layer 11 of the present invention.
Is provided. This porous reinforcing layer 11 is permanently bonded to the outer surface of the thin diaper backsheet 2 and provides a surface to which the free end 12 of the fastening tab 4 can adhere. The porous reinforcement layer is located near the edge region 7 so that when the free end 12 of the fastening tab 4 adheres to the porous reinforcement layer, the two edge regions 7 overlap and close to form a diaper undergarment. ing.
The porous reinforcement layer then exhibits the ability to provide a suitable surface for bonding the fastening tab free ends 12 under normal use conditions and when the reinforcement layer 11 is contaminated with oil.
When the free end 12 of the fastening tab 4 is connected to the porous reinforcing layer 11,
Typically, a foot opening 5 is provided which is provided with elastic means adapted to be sealed with the wearer's foot. In addition, the waist portion of the diaper may be elasticized in order to make the elasticity portion 6 fit the seal with the wearer. Prior to use, the adhesive surface on the free end 12 of the adhesive fastening tab 4 is protected from contamination by release coated paper or tape applied to the corners 7 of the inner face sheet 3. The backsheet 2 is typically a thin polyethylene film, while the topsheet 3 is typically a nonwoven such as spunbond polypropylene. Porous reinforcing layer 11
Is bonded to the backing sheet film by conventional means, including the use of hot melt adhesives.

The reinforcement layer 11 may be a single strip or a plurality of strips (eg, one for each fastening tab free end 12). The strip must be provided to cover the area to which the fastening tab free end 12 will adhere in normal use.

Oil stain tolerance is provided by a porous reinforcing layer that is lipophilic but provides a structurally cohesive surface. What is an agglomerated surface?
A surface that does not delaminate or break fibers (in the case of a web) when the free end 12 of the adhesive tab is peeled off. Such a porous layer generally has an effective pore diameter of 20 μm.
A microporous film or web having an effective pore size of 10 μm or less, preferably 1 μm or less. The holes are preferably continuous. However, some oil tolerance can also be imparted by a layer having discontinuous pores, such as a microporous film formed with a large number of discrete pores or a film having a large number of punched pores.

The porous reinforcing layer 11 is made of a microporous film or a cohesive nonwoven web (having an effective pore size of about 10 μm or less, preferably 1 μm or less).
), Preferably US Patent No.
No. 4,902,553, 4,539,256, 4,609,584, 4,726,989 or 4,824,719. The materials described in these patents were formed by dissolving a crystalline polymer material in a liquid additive at a temperature above its melting point, and forming the melt into a film, for example by extrusion. Including microporous film. The homogeneous solution is then cooled at a rate suitable to allow the crystalline polymer to crystallize to form a distinguishable continuous phase. The polymer is incompatible with the additive under ambient or use conditions. Thereafter, the hetero-phase film material is uniaxially or multiaxially stretched to obtain a film having micropores. The pores now contain the heterophasic liquid additive. The liquid additive preferably exhibits an affinity or plasticity for the adhesive on the free end of the fastening tab. Additives that can be used include saturated hydrocarbons such as mineral oil, glycerin, petroleum jelly, low molecular weight polyethylene, polyethylene oxide, polypropylene oxide, polytetramethylene oxide, soft carbowax, plasticized oil, and the like. The preferred additive is a plasticizing oil, of which mineral oil is particularly preferred because of its relatively low cost and excellent film-forming properties. The crystalline polymer material is preferably an olefinic, such as a polyolefin, or a condensation polymer, such as a polyester or polyamide. Most preferred are polyolefins such as crystalline isotactic polypropylene, polyethylene, polybutylene, polyethylpentene, copolymers, block polymers and modified versions thereof.

The additive liquid can be used in an amount of about 5 to 80%, preferably 5 to 50%, most preferably 10 to 30% by weight of the formed film.

Further, crystalline polymers and phase-separating additives are described in U.S. Pat. Nos. 4,247,498 and 4,100,238. For example, for isotactic polypropylene, poly-1-butene, polyethylene wax, low molecular weight polyethylene, alcohols, aldehydes, amines, esters such as methylene benzoate,
The use of phase-separating additives such as ethers, such as diphenyl ether, hydrocarbons or ketones, such as trans-stilbene, is described in the above-mentioned patents.

Nucleating agents such as those described in U.S. Pat. Nos. 4,824,718 and 4,726,989 can be used to uniformly crystallize the polymeric material upon cooling.
These nucleating agents are soluble in the liquid additive at a temperature at least 10 ° C. above the crystal transition temperature of the thermoplastic polymer, and at least one base material used in an amount of 0.05 to 5% by weight of the solution system. (Generally an organic acid or derivative), as well as any second inert nucleating agent used at about the same concentration. This second inert nucleating agent comprises an inorganic particulate material such as talc, titanium dioxide,
It typically contains calcium carbonate, magnesium carbonate, barium carbonate, magnesium sulfide, barium sulfide, and the like. Suitable organic acids include mono- or polyacids such as carboxylic acids, sulfonic acids, phosphonic acids, and solid organic alcohols such as dibenzylidene sorbitol.
Preferred organic acids are adipic and succinic acids, and a preferred second nucleating agent is talc.

After precipitation of the thermoplastic crystalline polymer, the film may be used without stretching, but is preferably 0 to 3, preferably 1.5 to 2.5.
It is preferable to use by stretching in at least one direction at a stretching ratio of. If the film is not stretched, it is preferable to wash off the liquid additive from the film.

Generally, the thickness of the microporous reinforced sheet is between 5 and 250 μm, preferably between 30 and 200 μm. Relatively thin films are preferred in terms of increased water vapor permeability and cost when used for this other purpose. However, if it is too thin, it may not be suitable for providing sufficient strength to prevent tearing of the back sheet of the diaper. The thicker the film, the better the tensile performance and the stronger the stronger adhesive.

By providing holes in the diaper back sheet material 2 behind the microporous reinforcing layer 11, for example, water vapor permeability for a diaper can be imparted. Generally, if holes are provided in a substantial portion (eg, over 2%, preferably over 5% open area) of the backsheet film coated with the microporous reinforcing layer, then rather small holes such as pinholes are used. Even so, a considerable amount of water vapor permeability can be imparted. In this arrangement, a porous liquid permeable (effective pore size greater than 1 μm) porous reinforced layer may be used, but is not preferred because it may wet the wearer's clothing.

Other porous reinforcement layers include microporous films without liquid additives, ie, films or highly consolidated nonwovens that have been made porous by mechanical means. Microporous films are typically made porous by blending solid particulates that are incompatible with the film-forming polymer and then stretching the particulate-containing film to create pores. Examples of suitable granules include calcium carbonate, magnesium carbonate, calcium sulfate and barium sulfate. These granules can be used in a range of about 5 to 80
%, Preferably from 40 to 70% by weight. The particle size range can be from about 0.1 to 250 micrometers. If the particle loading is small (for example, 5-20
(Around wt.%), The film does not exhibit the desired open pore structure or preferred porosity to improve oil contamination tolerance. Other suitable particulate fillers include talc, clay, silica, diatomaceous earth, alumina, mica, glass powder, asbestos powder, zeolites, zinc oxide, magnesium oxide or organic fillers such as polysiloxanes or other incompatible materials. Polymer or starch or cellulose powder,
For example, cellulose acetate is included, provided that their softening point is higher than the softening point of the film-forming polymer.

By removing the liquid additive from the liquid additive-containing porous film using an appropriate solvent having selectivity for the liquid additive, the non-liquid additive-containing microporous film (porous material not containing the liquid additive) Film). Various other methods of making microporous films or webs, such as cold stretching of crystalline film-forming polymers, are also suitable for forming microporous films containing non-liquid additives.

The pressure sensitive adhesive on the free end of the fastening tab is preferably an AB block copolymer, wherein the A and B blocks are tackified elastomers in a linear, radial or star configuration. A block has a molecular weight of 4,000
~ 50,000, preferably 7,000-30,000 monoalkenyl arenes, preferably polystyrene. The A block content is preferably about 10-50%, more preferably 10-30%.
%. Other suitable A blocks can be formed from alpha methyl styrene, t-butyl styrene and other ring-alkylated styrenes and mixtures thereof. The B block has an average molecular weight of about 5,000 to about 500,000,
Preferably from about 50,000 to about 200,000 elastic conjugated dienes. The elastomer preferably comprises at least 15% by weight, more preferably at least 25% by weight, of a block copolymer having a B-terminal block such as an AB diblock copolymer or a B-only elastomer, but most preferably the B-terminal block. Is an AB block copolymer having the following formula: The presence of these B-block terminated elastomers indicates that pressure-sensitive adhesives using elastomers containing these B-block terminated species contain liquid additives (especially when liquid additives are compatible with the elastomeric B blocks). situational)
It generally exhibits relatively high tack to microporous reinforced films (whether or not contaminated with oil) and relatively low tack to porous polyethylene films containing no liquid additives. It is generally preferred in that it is shown. A porous film that does not contain a liquid additive has a nonfunctionally high adhesive strength (for example, a 135 ° peel value of about 463 N / m) to a pressure-sensitive adhesive whose main component is an elastomer type having only an A block at the end. (Greater than 1,200 gm / in)). Further, the block copolymer containing the block at the terminal of the A block as a main component can be used for a long period of time, especially when the liquid additive is compatible with the B block, for example, when the liquid additive-containing microporous film is a mineral oil-based liquid additive. When in contact, there is a tendency to lose substantially all adhesion.

The tackifying component of the elastomeric adhesive generally includes a solid tackifying resin used in combination with or alone with the liquid tackifying resin and / or liquid plasticizer.
Preferably, the tackifying resin is selected from the group of resins that are at least partially compatible with the diene B portion of the elastic polymer or block copolymer. Such tackifying resins include unsaturated species having 4 to 6 carbon atoms, rosin esters and rosin acids, mixed aliphatic / aromatic tackifying resins,
Included are polyterpene tackifiers and aliphatic hydrocarbon resins produced by polymerization of feed streams containing hydrogenated tackifier resins as a major component. As a hydrogenated resin, a resin produced by polymerizing a feedstock containing dicyclopentadiene as a main component followed by hydrogenation; a resin produced by polymerizing a pure aromatic feedstock such as styrene and then hydrogenating it; 7 Comprising a resin produced by polymerizing and then hydrogenating an unsaturated feed stream containing as a main component a species containing up to 10 carbon atoms; and a hydrogenated aliphatic resin and / or an aliphatic / aromatic resin. Can also. Preferred tackifying resins include aliphatic hydrocarbon resins and their hydrogenated resins. Although not preferred, generally, a relatively small portion of the tackifying resin can include a resin compatible with the A block, if present, commonly referred to as a terminal block reinforced resin. Generally, these endblock resins are formed from aromatic species.

Liquid plasticizers suitable for fastening tab adhesive compositions include naphthenic oils, paraffinic oils, aromatic oils and mineral oils.

In general, the higher the composite glass transition temperature of the adhesive (e.g., greater than 250 Kelvin), the more non-contaminated and liquid contaminants that are contaminated with an amount of 0.1 to 0.2 milligrams or less oil per square centimeter. The adhesive ability becomes good even with the containing microporous film.

The tackifying portion of the pressure sensitive adhesive generally accounts for 20 to 300 parts per 100 parts of the elastomer phase. It is preferred that this is primarily a solid tackifier, but for adhesion to the polyethylene surface, 0-20% by weight of the adhesive, preferably 0-0
10% by weight may be a liquid tackifier and / or a plasticizer.

Based on other conventional pressure-sensitive adhesives, such as acrylate-based adhesives or other diene- or non-diene-based elastomers or natural rubber, together with the preferred liquid additive-containing porous film or non-liquid additive-containing porous film. An adhesive may be used.

The closure adhesive fastening tab is preferably about 386 N / m (1000 grams / gram) when adhered to a reinforcing layer or film.
And less than about 309 N / m (800 grams / inch). If the adhesive strength is higher than this value, it becomes difficult for the end user to peel off the tape, and for example, the diaper may be torn. Generally, the minimum allowable 135 ° peel force is about 19 N / m (50 grams / inch), but is preferably greater than about 30 N / m (80 grams / inch).

The liquid additive-containing film has an initial adhesion to a non-oil contaminated reinforced surface with the various pressure sensitive adhesives described above which is generally very close to the initial adhesion to an oil contaminated reinforced surface (excessively high). This is preferred in that it provides a closure with more consistent performance. Without wishing to be bound by theory, the liquid additive-containing reinforced film system reduces the adhesive strength of the adhesive when the reinforced strip is not contaminated with oil, while If contaminated, it may act to remove surface oil quickly from the surface.

The porous reinforcement layer generally presents an opaque appearance due to the pore structure. Certain hot melt adhesives used for applying to microporous films may make the film transparent or translucent. That is, when a uniform appearance is obtained by using these adhesives, it is preferable to apply the adhesive to the entire reinforcing layer or film. Also, some fastening tab adhesives tend to make the porous layer or film transparent, indicating a suitable location for reapplying the tape tab after opening.

The following examples are presently contemplated preferred embodiments of practicing the invention and should not be considered as limiting the invention.

Examples The following test methods were employed to evaluate porous reinforced films.

135 ° Peel Adhesion This test is a variant of PSTC-5. This test was performed at a constant temperature and humidity (21 ° C. and 50% relative humidity) using a constant speed Instron tensile tester. The film sample to be tested was adhesively fixed to a 2 inch × 5 inch (5.1 cm × 12.7 cm) steel panel using double-sided adhesive tape. Ten to sixty minutes after the film sample was secured to the steel panel, a 1 inch (2.54 cm) wide strip of test tape was placed on the film support with the adhesive side down and 4.5 lbs (2000 gm). Rolled down on the film support by passing twice through a hard rubber roller. The force required to release the fastening tape from the test support was reported in grams / inch in the table. The reported value is the average of two or more tests.

Shear adhesive strength Shear adhesive strength is 1 inch x 1 inch (2.5 cm x 2.5 cm)
The time required for the test tape sample to shear off from the film test support under a load of 1 kilogram was measured and measured. A 2 inch x 6 inch (5.1 cm x 15.2 cm) piece of reinforcing tape (3M Y-9377) to increase the rigidity of the support
A 2 inch × 6 inch (5.1 cm × 15.2 cm) film support piece was laminated. On the opposite side of the reinforcing tape, a 1 inch × 2 inch (2.5 cm × 5.1 cm) test tape was rolled down onto a film support by passing twice through a 4.5 lb (2000 gm) hard rubber roller. The overlap area between the test tape and the film support is 1 inch x 1 inch (2.5 cm x
2.5 cm). The support and test tape after lamination are 40 ° C
Was suspended vertically for 15 minutes in a furnace, and a 1 kg weight was suspended against the test tape to generate a shear load at an angle of 180 °. The time (minutes) required for the weight to fall was recorded as a measure of shear adhesion. The values reported are the average of five tests.

Oil contamination test: 135 ° of free film and oil contamination film
Peel Adhesion The test panel was a 2 "x 5" (5.1cm x 12.7c) with 0.75 "(1.9cm) double-sided adhesive strip secured along each 2" (5.1cm) lateral edge.
m) clean steel panels. The film test support sheet was laid loosely on the test panel so as to be flat without wrinkling. The transverse direction of the film support was parallel to the longitudinal direction of the test panel. The film was rolled down firmly on a double-sided adhesive and the excess of film that had run off the edge of the test panel was trimmed.

The film support side of the test panel was contaminated for testing by uniformly spraying the panel with a known amount of baby oil. The amount of adhering oil was measured by weighing each panel before and after spraying and was generally about 0.12 mg / cm ^2. Each panel after spraying showed 2 to 4 mg after oil spraying was completed. Tested in minutes.

Made another panel for comparison for the above test,
No oil spray was performed.

Each strip of test tape with a 1 inch x 8 inch (2.5 cm x 20.3 cm) paper leader attached to the last 0.25 inch (0.6 cm) section of the test tape was 1 inch x 2.5 inch (2.5 cm) × 6.5 cm). This tape assembly, the longitudinal direction of which is parallel to the longitudinal direction of the panel,
The tape was laid so that it was approximately equidistant from each lateral edge of the panel and centered between each longitudinal edge.
No additional pressure was applied when laying the tape. The tape was passed through a 100 gm rubber roller once and immediately rolled down at 12 inches (30.5 cm) / minute,
Tested within 15 seconds after the end of the rolldown.

An Instron (trade name) tensile tester was used for the peel test of this sample. 12 inch (30.5cm) sample test
The peel was performed at an angle of 135 ° at a constant crosshead speed of / min. The average peel force of each specimen is reported as the peel adhesion measurement in grams / inch in the table. Reported values are the average of four tests. The minimum allowable peel adhesion for this test is about 30 N / m for oil contaminated films (ie, those with an oil contamination of about 0.12 mg / cm ² ). The minimum peel adhesion of a tape that is peeled from a non-contaminated surface using the same test procedure must be about 40 N / m (about 100 gm / inch). These results were reported in gm / inch.

In the examples, the pressure-sensitive adhesives for the fastening tapes 1 to 9 were formulated from the following materials.

Kraton® 1107 is a polystyrene-polyisoprene linear block copolymer commercially available from Shell Chemical, having 14-18% diblocks, 80-85% triblocks, and having a styrene content of about 14%, and the Tg of the middle block is about 215 Kelvin.

Kraton (trade name) 1111 is a polystyrene-polyisoprene linear block copolymer commercially available from Shell Chemical Company having 14-18% diblocks, 80-85% triblocks, and having a styrene content of about What is 22%, and the Tg of the middle block is about 215 Kelvin.

Kraton® 1112 is a polystyrene-polyisoprene linear block copolymer, commercially available from Shell Chemical, having 40 diblocks, about 60% triblock, and about 14% styrene content. , And Tg of the middle block is about 215 Kelvin.

Kraton (R) RP-6411 is a polystyrene-polyisoprene linear block copolymer commercially available from Shell Chemical, having about 64% diblocks, about 36% triblocks, and having a styrene content of What is about 22%.

Cariflex IR-309 is a polyisoprene elastomer commercially available from Shell Chemical Company with a number average molecular weight of 390,000 and a Tg of 215 Kelvin.

Wingtack (trade name) 95 is a C ₅ tackifying resin Tg of 323 Kelvin solid which is commercially available from Goodyear Chemical Company.

Wingtack (trade name) Plus is a C ₅ tackifying resin Tg of 315 Kelvin solid which is commercially available from Goodyear Chemical Company.

Escorez (trade name) 1310, Tg, which is commercially available from Exxon Chemical Company is a C ₅ tackifying resin in 313.5 Kelvin solid.

Shellflex (trade name) 371 is commercially available from Shell Chemical Company and has an aromatic content of about 10 by the clay-gel analysis method.
% Is a naphthenic oil with a Tg of 209 Kelvin.

Zonarez (trade name) A-25 is a liquid alpha-pinene-based tackifying resin having a Tg of 251 Kelvin commercially available from Arizona Chemical Company.

Irganox (trade name) 1076 is a hindered phenolic antioxidant commercially available from Ciba-Geigy.

The block copolymer used to fasten tapes 7 and 8 was pure polystyrene-polyisoprene (S-I).
A mixture of a polyblock copolymer and a polystyrene-polyisoprene-polystyrene (S-I-S) triblock copolymer (triblock ≧ 87%). The total diblock% is as shown in Table 1, and the balance is substantially triblock.

Each pressure-sensitive adhesive composition is solvent-coated or hot-melt-coated on a polypropylene (polypropylene / polyethylene polymer blend for fastening tapes 5 and 6) film substrate (substrate thickness = about 4 mils). Fastening tapes 1 to 9 were produced. Composition of pressure sensitive adhesive (parts by weight)
And the thickness of the adhesive coating are listed in Table 1.

Examples 1-27 An oil-filled polypropylene microporous film (oils 15-35) stretched in one direction at a ratio of 1.6: 1, as described in U.S. Patent Nos. 4,539,256 and 4,726,989.
%). The oil was mineral oil (Amoco White mineral oil No. 31 commercially available from Amoco Oil). The 135 ° peel adhesion (according to both of the test methods described above), shear adhesion and oil stain tolerance of the fastening tapes 1-9 to the microporous film were tested. Table 2 shows the results. In Table 2, the microporous film samples are as follows: A = 35% oil, thickness about 43.2 μm (1.7 mil), B = 30% oil, thickness about 43.2 μm (1.7 mil), C = 25% oil, thickness It shows about 33.0 μm (1.3 mil), D = 20% oil, about 30.5 μm (1.2 mil) thick, and E = 15% oil, about 33.0 μm (1.3 mil) thick.

The effective pore size of the film A (according to ASTM F-316-86 measurement method) is 0.2 μm, and the effective pore size of the film C is 0.16
μm.

The oil-filled microporous film imparted a functional 135 ° peel performance to all tapes tested both with and without oil contamination. The shear performance of Tape Sample 1 was unacceptable except for low oil content microporous films. In general, tapes having an adhesive having a relatively high proportion of elastic (polyisoprene) end blocks, such as AB diblock copolymers (tapes 3 to 8), are remarkably excellent in peelability. However, the tape 4 due to the very low adhesive weight can be an exception. The best release performance was generally obtained for films with low oil content, less than about 30%.

Examples 28 and 29 Fastening tapes 1 and 5 against 1.4 micron thick polyethylene microporous film filled with particles (calcium carbonate)
Was tested. The Gurley value of the microporous film is (ASTM-D
-726-58, measured at Method A) 900 sec / 50 cc.
The results are shown in Table 3.

This film is believed to contain a small amount of process oil. The release performance of this film was excellent when contaminated with oil (Example 29).

Examples 30 and 31 Fastening tapes 1-9 were tested against a 0.75 mil thick polyethylene microporous film filled with particles (barium sulfate). The Gurley value of the microporous film is (ASTM-D-72
6-58, measured at Method A) 800 sec / 50 cc. Table 4 shows the results.

The film was very thin and generally torn when uncontaminated and unreinforced with oil (135 ° loose peel with a 100 gm roll down). However, this stripping performance, except for Tape 1 (which exhibits excessively high stripping properties to the film even when uncontaminated),
In general it was excellent.

Examples 37 and 38 Oil-washed thickness of about 43.2 μm as described in U.S. Patent Nos. 4,539,256 and 4,726,989
(1.7 mil) polypropylene microporous film (Example 3
7) and an oil-washed polyethylene microporous film of about 15.2 μm (0.6 mil) thickness (Example 38) was made. The film of Example 37 originally had 35% mineral oil and
The film originally had about 70% mineral oil and was washed with trichlorethylene to remove oil. Fastening tape 6 was tested on these washed films for 135 ° peel adhesion and oil stain tolerance. Table 5 shows the results. Example 38 was torn.

The oil stain tolerance of these films was excellent.

Examples 39-42 Adhesive tapes having an acrylate-based adhesive were tested for oil contamination on oil-filled polypropylene microporous films (35% and 25% oil, film samples A and C). The adhesive tape used in Examples 39 and 40 was Monta (trade name) 391 (commercially available from Monta, Germany), and the adhesive tape used in Examples 41 and 42 was Scotch
(Trade name) Magic (trade name) tape (No. 11257 commercially available from 3M Company, Germany). Table 6 shows the results.

Examples 43 and 44 Natural rubber adhesive tape (Y-commercially available from 3M)
9377), an oil-filled polypropylene microporous film (oil content
35% and 25%, film samples A and C) were tested for oil stain tolerance. Table 7 shows the results.

Comparative Examples 45-48 Fastening tapes 1 and 5 were applied to smooth biaxially oriented polypropylene (BOPP) film with low adhesive backing (LAB).
Both with coatings (Examples C45 and C46) and without LAB (Examples C47 and C48) were tested. Table 8 shows the results.

Tape 5 showed some oil tolerance, but the release performance was much worse than the release performance of this tape on oil contaminated microporous films. Tape 1 did not work well on oil contaminated non-porous films.

Comparative Examples 49-52 Fastening tapes 1, 5, 7, and 8 were tested against a conventional matte polyethylene film typical of that used for backing diaper disposable sheets. Table 9 shows the results.

Tapes 7 and 8 have the ability to adhere well to these polyethylene surfaces when contaminated with oil. However, the releasability on contaminated surfaces is less than one-third of the release performance on non-contaminated surfaces. This limited oil stain tolerance is due to the properties of the adhesive used in tapes 7 and 8. Peeling performance (contamination vs. non-contamination)
When adhered to a microporous film, tapes 7 and 8
The agreement was much higher for the adhesive.

Examples 53-68 Examples 53-68 show a polypropylene film substrate of about 102
This is an adhesive tape manufactured by applying an adhesive composition onto a μm (4 mil) solvent. The thickness of the adhesive of these tapes was about 32 μm. All of these adhesives were prepared from elastomers to which a solid tackifier had been added.

These tapes were tested against a conventional matte polyethylene film as used in the backsheet of disposable diapers. All of these tapes showed some oil contamination tolerance, among others, styrene content in the solid C ₅ tackifier or beta-pinene resin tackified 20
%, Preferably 22-26%, more than 60% by weight,
An adhesive containing preferably 65-85% by weight of the SI diblock copolymer in the elastomer phase provided the best oil release surface release performance.

In general, polystyrene-polyisoprene-based adhesives have oil contamination tolerance (peel force of 30 M / m or more) on the polyolefin surface, preferably on the polyethylene surface (containing 0.12 mg / cm ² at maximum). Was. In the above adhesive, the elastomer phase is more than 40% diblock (the remainder is triblock or other multi-block copolymer) and the styrene content of the elastomer is more than 13%,
It is preferably 15 to 30%, and the solid tackifier compatible with the isoprene block is 3 to 100 parts by weight of the elastomer.
It is used in an amount of 0 to 200 parts, preferably 40 to 120 parts, and no more than 15%, preferably less than 10%, of the adhesive composition is a liquid resin or plasticizing oil. Solid tackifier, C ₅ resins, C ₉ resins, preferably a beta-pinene resin or a rosin ester.

In general, these oil-tolerant adhesives exhibit a high release force on oil-contaminated surfaces and at the same time have an excessively high release force on oil-filled microporous films that have not been contaminated with oil. Preferred for use in porous films, oil stain tolerant reinforcing strips. These tapes also
It has the advantage of being able to adhere to non-porous polyethylene films contaminated with oil. This is useful if the porous reinforcement strip is lost.

These oil-tolerant adhesives adhere well to the polyethylene film, especially when the polyethylene film is reinforced on the inner surface opposite the outer surface to which the adhesive tape is joined, for example by a plastic strip or tape of the film.

Example 69 The fastening tape 5 was tested against a porous highly compressed nonwoven polyethylene web (Tyvel® 1422R) having an effective pore size of 9 μm. One side of the web was embossed. Using the above loose peel test, a 135 ° peel test was performed on both sides, both with and without oil contamination. The peel force of the embossed surface was about 51 μm (131 gm / inch) and about 28 N / m (72 gm / inch) for the non-oil contaminated film and the oil contaminated film, respectively. Peeling adhesion of smooth surface is about 31N / m (81gm / inch) and about 12μ respectively.
m (31 gm / inch). These films showed low release values for the non-staining release test, indicating the presence of a surface treatment. However, this web exhibits oil stain tolerance.

Example 70 Approximately 24 x 15 cm (9.5 in x 25 in) of 25% oil including print
A 6 inch) film sample (porous film C) was laminated on the acrylate transfer adhesive and a 4.5 lb roller was rolled. This transfer adhesive was produced by pulling RD-975 (manufactured by 3M) having a coating weight of 5 g on the release liner. Next, a slit was made in this laminate, and a sample of about 24 × 5 cm (9.5 inches × 2 inches) was placed on a Pamper.
s (trade name) laminated on the front of the diaper. The sample was then rolled with a roller of about 2 kg (4.5 lb) to smooth it without wrinkles. The resulting diaper had a functional soil tolerance enhancing strip.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kinney, Robert Jay. Minnesota 55133-3427, United States, St. Paul, post office box 33427 (no address) (72) Inventor Gobelin, Ramsis United States, Minnesota 55133-3427 St. Paul, Post Office Box 33427 (No Address) (72) Inventor Velazquez Array, Leuven E. United States, Minnesota 55133-3427, St. Paul, Post Office Box 33427 (No Address) (72) Inventor Midgray , Roland Earl. Minnesota 55133-3427, St. Paul, post office box 33427 (no address). (56) References JP-A-59-228008 (JP, JP-A-63-309605 (JP, A) JP-A-62-282003 (JP, A) JP-A-58-149303 (JP, A) JP-A-63-161035 (JP, A) JP-A-1- 162804 (JP, A) JP-A-54-145740 (JP, A) JP-A-59-69906 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61F 13/58 A61F 5 / 44

Claims (8)

(57) [Claims] 1. A disposable garment comprising a thin liquid impervious sheet material and an oil contamination tolerant closure system, wherein the closure system includes a pressure sensitive adhesive fastening tab and a free end of the fastening tab. A closure layer for closing the disposable garment, wherein the fastening tab is permanently bonded to a first edge region of the garment at a second end opposite its free end, wherein the reinforcement layer comprises Bonded to an outer surface of the thin liquid impervious sheet material near a second edge region of the reinforcement layer, wherein the reinforcing layer comprises an oil-absorbing porous sheet material;
The reinforcing layer is a microporous film or a compressed non-woven fabric having an effective pore size of less than 20 μm, and two separate edge areas overlap and close the garment when the free end of the fastening tab adheres to the reinforcing layer. Disposable clothing. 2. The microporous film comprises a liquid additive containing film, wherein the liquid additive comprises 5 to 50% by weight of the film and forms different phases within the polymer film, and The disposable garment according to claim 1, wherein the additive is selected from plasticizing oil, glycerin, petroleum jelly, soft carbowax, low molecular weight polyethylene, polyethylene oxide, polypropylene oxide, polytetramethylene oxide or a mixture thereof. 3. A thin liquid impervious sheet material, a free end for including at least one binding area on said thin sheet material and adhering to said binding area and a first of said garment.
A pressure-sensitive adhesive closure system having a pressure-sensitive adhesive fastening tab having an opposite second fastening tab end permanently bonded to an edge region of the disposable garment. 2 having an outer surface of a polyolefin, which is provided near the edge region of No. 2 and comprising: a) a diblock copolymer having a styrene content of 13% or more.
100 parts of an AB type polystyrene-polyisoprene elastomer containing 40% by weight or more, 30 to 200 parts of an isoprene block-compatible solid tackifier, and 0 to 15% by weight of a liquid resin or a plasticizing oil, or b) comprising an acrylate adhesive, wherein when the free end pressure-sensitive adhesive is applied to the outer surface of the at least one bonding area, the fastening tabs may have an amount of 0.12 mg / cm ² or less of mineral oil on the outer surface of the polyolefin. The disposable garment providing a 135 ° peel force (100 gm / roll down) of 30 N / m or more to the at least one bonding region. 4. A thin liquid impervious sheet material, a free end for including at least one binding area on said thin sheet material and adhering to said binding area, and a first of said garment.
A pressure-sensitive adhesive closure system having a pressure-sensitive adhesive fastening tab having an opposite second fastening tab end permanently bonded to an edge region of the disposable garment. And a polyolefin exterior surface provided near the second edge region and having a polyolefin exterior surface, the at least one bonding zone polyolefin exterior surface includes a microporous film containing a liquid additive, and the free-end pressure sensitive adhesive is provided with the at least one adhesive. When applied to one join area,
The fastening tab has a thickness of 0 to 0.12 mg / cm ^{2 on the} outer surface of the polyolefin.
Said disposable garment providing a 135 ° peel force (100 gm / roll down) of at least 30 N / m to said at least one bonding region containing an amount of mineral oil. Wherein said pressure sensitive adhesive comprises 0-15 percent by weight plasticizing oil or liquid tackifier, said solid tackifier is C ₅
Resins, C ₉ resins, beta - a-pinene resin or a rosin ester and said elastomer is styrene content 20
4. The disposable garment according to claim 3, comprising 60% or more of the diblock copolymer of 60% or more. 6. The method according to claim 3, wherein said at least one bonding area comprises a reinforced zone provided by a plastic film strip or tape backing on the inner or outer surface of said thin liquid-impermeable sheet material. Disposable clothing as described. 7. The elastomer according to claim 1, wherein the styrene content is 22 to 22.
6. The disposable garment of claim 5, comprising 26-65% by weight diblock, and wherein the adhesive comprises 40-120 parts of a solid tackifier. 8. The polyolefin exterior surface of the at least one binding region includes the thin liquid impervious sheet material.
The disposable garment according to claim 3 or 4.